1. Field of the Invention
The invention relates to a circuit arrangement for amplifying a television signal, having, arranged between an input and an output, a differential amplifier comprising two emitter-coupled transistors.
2. Description of Related Art
Circuit arrangements of this type are known and are used, more specifically, in integrated circuits, for example to amplify a television signal in the baseband. These integrated circuits are standardized for a power supply of 12 V and amplify the television signal on a voltage swing of, typically, 1 to 2 V. Such arrangements must satisfy high requirements as regards their gain factor, linearity and stability, their assembly must be effected in an integrated circuit production method which is easy to maintain and consequently must be inexpensive, and the circuit arrangements themselves must be of a simple space-saving construction. In the known circuit arrangements, these requirements are satisfied in that the voltage swing of the television signal remains small relative to the supply voltage.
To reduce the power consumption of television receivers and like apparatus, it is desirable to reduce the supply voltages for circuit arrangements incorporated therein for the processing of television signals, to a value which is located in the order of magnitude of the voltage swing of the television signal, more specifically to, for example, 5 V. This renders it possible to run the television receiver from a battery.
On the other hand, given signal transmission properties require currents which, with the object of power reduction, cannot be optionally reduced. It has been found that the circuit concepts which have been used so -ar for this case no longer satisfy the requirements to be imposed on the processing of television signals, particularly as regards linearity and stability.